About Area Code 406

Area Code 406 Map

Billings, MT

Bozeman, MT

Butte-silver Bow, MT

Great Falls, MT

Helena, MT

Missoula, MT

More About Area Code 406

Area code 406 is one of the original 86 area codes created by AT&T and the Bell System in 1947. It originally served the entire state of Montana. Currently, it covers the entire state of Montana, and it overlaps coverage areas with area code .